Andrew M. answered • 12/07/15

Tutor

New to Wyzant
Mathematics - Algebra a Specialty / F.I.T. Grad - B.S. w/Honors

The reciprocal of a number x is 1/x

The difference of the reciprocal of a number and 3/10 means:

1/x - 3/10 or 3/10 - 1/x

is means equals so:

Let's take the first situation:

1/x - 3/10 = 1/5

1/x = 3/10 + 1/5

1/x = 5/10

1/x = 1/2

x = 2

Check answer: 1/2 - 3/10 = 1/5

5/10 - 3/10 = 1/5

2/10 = 1/5

1/5 = 1/5

Answer checks as correct:

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Looking at the 2nd situation:

3/10 - 1/x = 1/5

1/x = 3/10 - 1/5

1/x = 1/10

x = 10

check: 3/10 - 1/10 = 1/5

3/10 - 1/10 = 1/5

2/10 = 1/5

1/5 = 1/5

So there are two answers which fit the criteria of the problem.

x = 2 and x = 10

Note: Most times the wording "the difference between the

reciprocal of a number and 3/10 would be interpreted as

1/x - 3/10 so your teacher may only be expecting the

answer x = 2

Andrew M.

Norbert,

I had this exact conversation on here before and my position was the one you just espoused. Other tutors argued that both answers are valid. My research is inconclusive.... But, as stated, I agree that the teacher expects the answer to be x=2.

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12/07/15

Andrew M.

the diference between 1 and 3...

1-3=-2

3-1=2

The distance, or absolute value, is the same and many argue that both are valid answers. Take it fir what it's worth.

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12/07/15

Norbert J. M.

12/07/15